This atom-by-atom simulation shows a crack spreading through a brittle material. First the crack creates a clean slice across the surface, but as it gains speed it starts to gyrate, and the cracks path becomes increasingly uneven. Image/Markus J. Buehler, MIT
An MIT researcher’s atom-by-atom simulation of cracks forming and spreading may help explain how materials fail in nanoscale devices, airplanes and even in the Earth itself during a quake. This work, which could impact a wide range of scientific and engineering disciplines, appears in the Jan. 19 issue of Nature.
"Classical theories of crack dynamics are only valid in a small range of material behavior," said author Markus J. Buehler, principal investigator in the Atomistic Mechanics Modeling Group in MIT’s Department of Civil and Environmental Engineering. "Our results represent a major breakthrough in understanding how cracks propagate in a variety of brittle materials, and our theory helps explain experimental and computational observations that have been poorly understood so far."
Past experiments show that cracks start out slow, creating a straight, clean slice across a flat-as-a-mirror surface. As the crack gains speed, at a certain point it starts to gyrate like an out-of-control snake, leaving in its wake an increasingly rough, uneven surface that eventually creates a chaotic branching pattern.
Elizabeth Thomson | MIT
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